The present invention relates to a method and apparatus for placing sutures in tissue, and more particularly to a method and device for arthroscopic repair of a torn rotator cuff.
Suturing of body tissues is a time consuming aspect of most surgical procedures. Many surgical procedures are currently being performed where it is necessary to make a large opening to expose an area of the body that requires surgical repair. Endoscopes are available for viewing certain interior regions of the body through a small puncture wound without exposing the entire body cavity. These instruments can be used in conjunction with specialized surgical instrumentation to detect, diagnose, and repair areas of the body that were previously only able to be repaired using traditional xe2x80x9copenxe2x80x9d surgery.
In the past, there have been many attempts to simplify the surgeon""s task of driving a needle carrying suture material through body tissues to approximate, ligate and fixate them. Many prior disclosures, such as described in U.S. Pat. No. 919,138, to Drake et al., issued Apr. 20, 1909, employ a hollow needle driven through the tissue with the suture material passing through the hollow center lumen. The needle is withdrawn leaving the suture material in place, and the suture is tied, completing the approximation. A limitation of these types of devices is that they are particularly adapted for use in open surgical procedures where there is room for the surgeon to manipulate the instrument.
Others have attempted to devise suturing instruments that resemble traditional forceps, such as U.S. Pat. No. 3,946,740 to Bassett, issued Mar. 30, 1976. These devices pinch tissue between opposing jaws and pass a needle from one jaw through the tissue to the other jaw, where grasping means pull the needle and suture material through the tissue. A limitation of these designs is that they also are adapted primarily for open surgery, in that they require exposure of the tissues to be sutured in order that the tissue may be grasped or pinched between the jaws of the instrument. This is a severe limitation in the case of endoscopic surgery.
The term xe2x80x9cendosurgeryxe2x80x9d means endoscopic surgery or surgery performed using an endoscope. In conjunction with a video monitor, the endoscope functions as the surgeon""s surrogate eyes for the purpose of performing the surgical procedure. Operations using an endoscope are significantly less invasive when compared to traditional open surgery. Patients usually return home the next day or in some cases, the same day of the endosurgical procedure. This is in contrast to standard open surgical procedures where a large incision divides the muscle layers and allows the surgeon to directly visualize the operative area. Patients may stay in the hospital for 5 to 6 days or longer following open surgery. In addition, after endosurgical procedures, patients often return to work within a few days versus the traditional 3 to 4 weeks recuperative period following open surgery.
Access to the operative site using endosurgical or minimally invasive techniques is accomplished by inserting small tubes called trocars into a body cavity. These tubes have a diameter of, for example, between 3 mm and 30 mm and a length of about 150 mm (6 inches). There have been attempts to devise instruments and methods for suturing within a body cavity through these trocar tubes.
Such an instrument is disclosed in U.S. Pat. No. 4,621,640 to Mulhollan et al., issued Nov. 10, 1986. Mulhollan et al. describe an instrument that may be used to hold and drive a needle, but make no provision for retrieval of the needle from the body cavity, nor the completion of the suture by tying. The instrument disclosed in the Mulhollan et al. patent is limited, in that the arc through which the needle must be driven is perpendicular to the axis of the device.
Another such instrument intended for endoscopic use is described by U.S. Pat. No. 4,935,027 to Yoon, issued Jun. 19, 1990. This instrument uses oppositional hollow needles or tracks pushed through the tissue and co-apted to create a tract through which the suture material is pushed. It is not clear from the disclosure how these curved tracks would be adapted to both be able to pierce the tissue planes illustrated, parallel to the tips of the tracks, and be curved toward each other to form the hollow tract.
Yet another instrument and method is shown in U.S. Pat. No. 4,923,461 issued May 8, 1990 and U.S. Pat. No. 4,957,498 issued Sep. 18, 1990, both to Caspari. Caspari discloses an endoscopic instrument suitable for use through a trocar, that resembles the Yoon approach, but with a single hollow needle on one of a set of oppositional jaws. The jaws simultaneously close, grasping the tissue. The jaw opposite the hollow needle has a window through which the hollow needle passes as the jaws close, freeing the lumen of the hollow needle from the tissue. Much like the Yoon patent, a suture or suture snare is pushed down through the lumen and retrieved from the suture site, the jaws released, and the suture pulled back out through the trocar. This device may be used to place simple stitches in tissues that have been mobilized and have an edge accessible to the jaws. A limitation of the device is the manipulation that must be done with the snare if a suture other than a monofilament is used.
Another instrument specifically adapted for the repair of a tom anterior cruciate ligament or for meniscal repair is disclosed in U.S. Pat. No. 4,836,205 to Barrett. The Barrett patent combines in a single instrument the functions of grasping the tissue to be sutured and the passing of the needles through that tissue. It is to be understood that this instrument is designed for use specifically under endoscopic view, and through trocars as previously described. A fairly generic endoscopic grasper is disclosed that has been adapted to allow for a hollow lumen from the handle of the grasper down to the distal tip of the grasper jaws. An elongate needle of 8 to 10 inches in length may be passed through this hollow lumen. The needle, being significantly longer than the grasper, is introduced through the handle of the grasper, and may be driven through the tissue being held in the grasping jaws of the device. The needle is then retrieved from the tissue via a trocar port placed substantially opposite the port through which the grasper is introduced. If a mattress stitch is desired, two needles attached to opposite ends of a suture are both passed through the tissue and retrieved. A limitation of this device is that there must be both visual and physical access to both sides of the tissue flap to be sutured. This requires trocars to be placed opposite each other and roughly on a line intercepting the tissue. This is a severe limitation in the instance of shoulder repair, and specifically in repair of the rotator cuff.
There have been other attempts to improve the methods of tissue repair. These include the development of staplers and anchoring devices. In response to some of the aforementioned problems in placing sutures in tissues endoscopically, manufacturers have developed tissue staplers. These devices utilize stainless steel or titanium staples that are constructed much like the staples used to hold papers together. The major disadvantage of these kinds of staplers is that they leave metal in the body. For some tissues this is not a problem, however in some procedures, metal staples left within the tissues can be a major hindrance to the healing process.
In orthopedic surgery, many different designs for bone anchors have been developed. These anchors allow soft tissues to be reattached to bone, and simplify the process by removing the need to create a trans-osseous tunnel. Trans-osseous tunnels are created in bones to allow suture material to be threaded through and tied across the bony bridge created by tunnels after it has been placed through the soft tissues and tied with conventional knots. Anchors fabricated from stainless steel or titanium are commonly used in joint reconstructions, and because the metal is contained in the bone, it does not typically cause a problem with healing.
While endoscopy has certainly found favor with many physicians as an alternative operative modality, the advanced skill set and operative time necessary to become an efficient and practiced endoscopist have proven to be a challenge for a large portion of the surgical community. The cost pressures brought about by large scale patient management (the continued rise and success of health maintenance organizations or HMO""s) have also caused the surgical community to carefully evaluate the overall costs and long-term outcomes of some of the procedures that have been tried via an endoscopic approach. While the laparoscopic cholecystectomy (gall bladder removal) has well proven its worth in the past 8-10 years, many other procedures have not shown similar cost effectiveness and positive long-term outcomes.
Hence, alternatives have been sought to bridge the gap between skill and equipment intensive endoscopic surgery and more familiar open surgery. As such, under the broad umbrella of xe2x80x9cminimally invasive surgeryxe2x80x9d which would include endoscopic surgery, a relatively new approach called xe2x80x9cmini-incision surgeryxe2x80x9d has begun to emerge. This approach uses the principles of traditional open surgery, along with some of the equipment advances of endoscopy in an attempt to provide the patient with the best of both worlds.
Perhaps the most visible of these new approaches is the emergence of minimally invasive heart surgery, both for coronary bypass and for valve replacement. Techniques and tools for cardiovascular surgery have begun to be used that allow the heart surgeon to perform procedures through small incisions between the ribs that previously required a massive incision and splitting of the sternum to gain access to the heart.
In a similar way, orthopedic surgeons have begun to explore alternatives to the traditional open approach for the many indications requiring reconstruction of some aspect of the shoulder. As they did in adopting minimally invasive approaches to knee repair and re-construction, the use of either an endoscope or a xe2x80x9cmini-openxe2x80x9d approach is gaining in popularity with surgeons, patients and third party payers.
It is an increasingly common problem for tendons and other soft, connective tissues to tear or to detach from associated bone. One such type of tear or detachment is a xe2x80x9crotator cuffxe2x80x9d tear, causing pain and loss of ability to elevate and externally rotate the arm. Complete separation can occur if the shoulder is subjected to gross trauma, but typically, the tear begins as a small lesion, especially in older patients.
The rotator cuff of a shoulder joint is made up of a combination of the distal tendinous portion of four muscles, supraspinatus and subspinatus, subscapularis and teres minor. The cuff is attached to the upper, anterior and posterior faces of the trochiter by covering the upper pole of the humeral head. Proper functioning of the tendinous cuff, 3 to 4 millimeters thick, depends on the fundamental centering and stabilizing role of the humeral head with respect to sliding action during anterior and lateral lifting and rotation movements of the arm.
The musculotendinous cuff passes under an osteofibrous arch, which is made up from the front to the rear by a portion of the acromion, the coracoacromial ligament and the coracoid process, thereby forming a canal. A sliding bursa passes between the musculotendinous cuff and the walls of the osteofibrous arch. Therefore, there is a potential and sometimes detrimental interaction between the musculotendinous cuff and the acromiocoracoidian arch, particularly during lateral and anterior lifting movements of the arm. The repeated rubbing of the cuff against the walls of the osteofibrous arch results in wearing of the tendinous cuff by progressive abrasion. The rubbing can be increased, inasmuch as arthosis lesions with severe osteophytes may thicken the walls of the aforementioned arch, becoming more aggressive as the cuff gets older.
With time, gradual thinning is brought about, often resulting in a trophic perforation (less than 1 cm2) of the cuff, particularly in the hypo-vascularized and fragile area where the supraspinatus muscle is joined. A fall may provide a more extensive rupture by disjunction of the supraspinatus muscle, with extension towards the front (subscapularis muscle) or the rear (subspinatus muscle). The degenerative rupture of the rotator or musculotendinous cuff may be of a varied size:
grade 1xe2x80x94perforation (less than 1 cm2) reaching the supraspinatus muscle;
grade 2xe2x80x94supraspinatus rupture (greater than 1 cm2);
grade 3xe2x80x94massive rupture concerning the supraspinatus, subspinatus, subscapularis muscles and sometimes the teres minor muscle.
It is possible to carry out surgery to reconstruct the rotator cuff. This is done by re-covering the humeral head, giving back to the cuff its capturing and stabilizing role and re-establishing a harmonious scapulohumeral rhythm. Reconstruction requires excision of the coracoacromial ligament and cleaning of the subacromial space, including suppression of the arthrosis legions and thinning of the anterior portion of the acromion.
The typical course for repair of a tom rotator cuff today is to do so through an open incision. This approach is presently taken in almost 99% of rotator cuff repair cases. Two types of open surgical approaches are employed for repair of the rotator cuff, one known as the xe2x80x9cclassic openxe2x80x9d and the other as the xe2x80x9cmini-openxe2x80x9d. The classic open approach requires a large incision of 6 to 9 centimeters (cm) and complete detachment of the deltoid muscle from the acromion to facilitate exposure. Following the suturing of the rotator cuff to the humeral head, the detached deltoid is surgically reattached. Because of this maneuver, the deltoid requires postoperative protection, thus retarding rehabilitation and possibly resulting in residual weakness. Complete rehabilitation takes approximately 9 to 12 months.
The mini-open technique, which represents the current growing trend and the majority of all surgical repair procedures, differs from the classic approach by gaining access through a smaller incision of 3 to 5 cm and splitting rather than detaching the deltoid. Additionally, this procedure is typically used in conjunction with arthroscopic acromial decompression. Once the deltoid is split, it is retracted to expose the rotator cuff tear. The cuff is debrided and trimmed to ensure suture attachment to viable tissue and to create a reasonable edge approximation. In addition, the humeral head is abraded or notched at the proposed soft tissue to bone reattachment point, as healing is enhanced on a raw bone surface. A series of small diameter holes, referred to as trans-osseous tunnels, are xe2x80x9cpunchedxe2x80x9d through the bone laterally from the abraded or notched surface to a point on the outside surface of the greater tuberosity, commonly a distance of 2 to 3 cm.
There are a few different methods for placing the suture material in the supraspinatus tendon. Because one of the most common failure modes for rotator cuff repair lies in the sutures pulling out of the soft tissue, much care is taken to place the sutures such that the most security possible is achieved. This is typically done by using either a mattress stitch or a more complex stitch called a xe2x80x9cmodified Mason-Allenxe2x80x9d. The goal of both of these stitches is to spread the forces imparted by the sutures on the tissues by involving a pledget of tissue between the entry and exit points of the suture ends. The mattress stitch incorporates essentially a xe2x80x9cdown, over and back upxe2x80x9d path for the suture.
Finally, the cuff is secured to the bone by pulling the suture ends through the trans-osseous tunnels and tying them together using the bone between two successive tunnels as a bridge, after which the deltoid muscle must be surgically reattached to the acromion.
Although the above described surgical technique is the current standard of care for rotator cuff repair, it is associated with a great deal of patient discomfort and a lengthy recovery time, ranging from at least four months to one year or more. It is the above described manipulation of the deltoid muscle together with the large skin incision that causes the majority of patient discomfort and an increased recovery time.
Less invasive arthroscopic techniques are beginning to be developed in an effort to address the shortcomings of open surgical repair. Working through small trocar portals that minimize disruption of the deltoid muscle, a few surgeons have been able to reattach the rotator cuff using various bone anchor and suture configurations. The rotator cuff is sutured intracorporeally using instruments and techniques such as the Caspari punch previously described. This creates a simple stitch instead of the more desirable mattress or Mason-Allen stitch. Rather than thread the suture through trans-osseous tunnels which are difficult or impossible to create arthroscopically using current techniques, an anchor is driven into bone at a location appropriate for repair. The repair is completed by tying the cuff down against bone using the anchor and suture.
Early results of less invasive techniques are encouraging, with a substantial reduction in both patient recovery time and discomfort. However, as mentioned, this approach places only one loop of suture in the cuff for each anchor, reducing the fundamental strength of the repair. The knots in the tendon can be bulky and create a painful impingement of the tendon on the bone. This is because the knots end up on top of the cuff, in the sub-acromial space, and have the opportunity to rub on the acromion as the arm is raised. Because non-absorbable suture materials are used for these types of repairs, the suture and associated knots are not absorbed into the body, and hence provide a constant, painful reminder of their presence.
None of the prior art devices are adaptable to effect the placement of a mattress stitch in grasped tissues, nor are they adaptable to place sutures precisely and controllably while making provision for needle retrieval when using endoscopic techniques. None of the prior art devices make it possible to place a mattress stitch into, for example, the supraspinatus tendon utilizing an endoscopic approach.
Accordingly, it would be desirable to provide a family of novel suturing devices that overcomes the above set out disadvantages of prior known devices in a simple and economical manner. In particular, a system which would be capable of creating a mattress stitch in the tendon, using endoscopic techniques, to increase the soft tissue pullout strength would be advantageous, as would a system that does not require the traditional knots to secure the suture to the tendon.
Accordingly, a new and novel approach to securing a mattress stitch in a tissue flap has been developed. An instrument that combines the function of both grasping the tissue and passing sutures through the tissue to form a mattress stitch, in an endoscopic environment, is herein described.
In the method of the present invention the instrument is inserted through a portal known as a trocar cannula. The portal is created by first making an incision in the skin and then inserting a cannula through the incision to the repair site. The distal end of the instrument is inserted through the cannula under direct visualization from a second trocar cannula that has been previously inserted. The visualization is accomplished via an endoscope, which is well known in the art. The instrument is inserted until the jaws reach, for example, torn rotator cuff tissue. In operation, the distal end of the grasper aspect of the instrument is positioned at the repair site against the tissue to be grasped. The moveable jaw is pivoted toward the stationary jaw by squeezing the handle lever. As the handle lever moves inwardly by pivoting about a pivot pin, a cable attached to the top of the handle lever is drawn rearwardly, proximal of the handle. When the cable is drawn rearwardly, the movable jaw pivots towards the stationary jaw to close the jaws. Once the appropriate section of tissue is isolated and grasped by the jaws, the lever may be locked in its closed position using a latch mechanism.
Once the surgeon is satisfied with the placement of the grasper on the grasped tissue, the surgeon can then deploy the suture needles to create a mattress stitch in the tissues, for example, a torn rotator cuff. In operation, the suture needles may be advanced through the grasped tissues by pulling on a trigger. The trigger is attached to a slide cable, and pulling on the trigger draws the slide cable rearwardly towards the proximal end of the instrument, pulling against the force of a return spring. In turn, the slide cable pulls a needle carriage with suture needles releasably held in the carriage. The needle carriage resides within the lower stationary jaw of the instrument, and at the urging of the trigger via the slide cable, is able to move from distal to proximal locations within the jaw. As the carriage moves proximally, the tips of the suture needles begin to clear the distal edge of an aperture created in the lower stationary jaw and begin to penetrate through the underside of the grasped tissue and advance upwardly towards the movable jaw.
In one preferred embodiment, the needle carriage is coupled to the needles by a set of tabs that engage shoulders on the needles. The shoulders of the needles are formed by the proximal end of the needle holding the suture, and an outer sleeve that is slidably disposed about a flexible inner ribbon affixed to the proximal end. The ribbon has attached to its distal end a needle tip which limits the distal travel of the outer sleeve and creates the second shoulder at the proximal end of the outer sleeve.
In the aforementioned embodiment, the moveable jaw incorporates a passive needle catch. The jaw is constructed with a window in the face of the jaw to allow the needles to penetrate through to a passive catch that incorporates a thin stainless steel membrane with slots configured to capture the tips of the needles. As the suture needles approach the end of the ejection stroke, the distal ends of the needles pass through the upper movable jaw and the capture member. As the needles pass through the upper jaw they begin to separate from the needle carriage. The proximal end of the needles"" curved outer sleeve separates from the first tab on the needle carriage, in such a manner that there is no further force pushing on the sleeve to force it through the tissues. The force now pushing on the suture needles is concentrated on the proximal end of the needles. As the needle carriage is advanced further, the needles"" curved outer sleeves stay stationary due to the resistance caused by their contact with the tissues. However, the flexible inner ribbon of each needle is free to advance further. The gap between the needles"" curved outer sleeves and the proximal end of each needle begins to close until there is no gap at all. At this point the penetrating tip of each needle has extended beyond the distal end of the needle""s curved outer sleeve, exposing the flexible inner ribbon. Once the gap is closed between the proximal end of the needle and the outer sleeve, the needle assembly will again continue to advance as one unit through the grasped tissues. As the needle carriage advances further, it pushes on the needle assembly until each needle has been pushed beyond the point of contact with the needle carriage. At this point the suture needles are through the grasped tissues and protruding through the upper movable jaw and into the needle catch. Due to a pre-defined curve in the flexible inner ribbon, the penetrating tip remains extended from the distal end of each needle""s curved outer sleeve.
At this point, any pull force being applied by the grasper on the grasped tissues is relaxed. Once the tissue is in a relaxed state, the jaws of the grasper are then opened. The handle lever is unlocked from the locking mechanism and returns to an open position due to the pull force exerted on it by means of a return spring. As the return spring pulls on the lever, it pivots about a pin. As handle lever pivots, it pulls on the jaw cable coupled to the handle lever by means of a pin. This advances the jaw cable towards the distal end of the barrel. As the jaw cable advances, it pushes on a linkage which then pushes on the movable upper jaw, causing the upper jaw to pivot about a pin. This pivoting motion causes the moveable jaw to open and separate away from the stationary jaw. As the movable upper jaw begins to open, the suture needles for the most part remain stationary due to resistance caused by their contact with the tissues through which they have been driven. At a point just beyond the distal end of the suture needle""s curved outer sleeve, the needle catch on the upper jaw will trap the suture needles at a point between the curved outer sleeve and the penetrating tip, grasping the flexible inner ribbon and securing the needles by interference with the shoulder created between the inner ribbon and the penetrating tip.
As the upper jaw slips past the needle""s outer sleeve, the small slit in the needle catch closes down around the needle""s ribbon. The slit is large enough so as not to restrict the movement of the ribbon, but is too small to allow the penetrating tip to pass back through. This is because the needle catch on the upper jaw can only be deflected in an outward direction, away from the outer surface of the upper jaw. Since the distal end of the suture needles are trapped in the needle catch on the upper jaw, they are pulled through the tissues as the upper jaw is opened further.
When the jaws of the grasper are fully extended, the suture needles are nearly pulled through the tissue. To complete the pullout of the suture needles, it is necessary to pull on the grasper, and begin to remove it from the repair site. Once the suture needles are through the tissue, they can be secured by closing down the jaws of the grasper. After closing the grasper jaws, the instrument can be retracted back through the portal via the trocar cannula.
As the instrument is removed from the suture site, the free ends of the suture are retrieved as well. This causes the suture to pass through the tissues at the puncture sites. As the suture is pulled through, the loop end of the suture is pulled snug against the underside of the tissues to form what is referred to as a mattress stitch. This process may be repeated as necessary, depending on the number of sutures required for the particular procedure being undertaken.
The instrument may be reloaded with new suture needles by removing an end cap covering the distal end of the lower stationary jaw. After the end cap is removed, the needle carriage may be advanced beyond the distal end of the lower jaw to be reloaded. To advance the needle carriage in this manner simply requires advancing the handle trigger towards the distal end of the grasper. Once new suture needles are reloaded, end cap may be replaced. The excess suture loop that will form the next stitch passes through the lower stationary jaw through a small notch. This extra length of suture is left outside the body as the grasper is inserted back through the portal to the repair site as previously described.
Another embodiment of the grasper/suturing device modifies the needle and suture interface. Instead of the needle carrying the suture by an attachment point at the distal end of the needle, this embodiment releasably attaches the suture to the needle at nearly the proximal end. The major elements of the above described instrument remain the same; i.e. the grasper function with a lower fixed jaw and an upper moveable jaw, and a needle carriage coupled to a trigger for actuation of the stitching function.
However, in this second embodiment, the needles are non-releasably attached to the needle carriage; that is to say that they are permanently attached to the carriage. The suture, which is of a braided configuration that is known in the art and has a hollow core, is configured to have a ferrule attached to its ends. This ferrule is constructed such that the hollow braided suture is crimped or otherwise mechanically or adhesively attached to the ferrule. The ferrule includes an interior lumen which is dimensioned such that it is able to be slidably disposed over the end of the needles which are attached to the needle carriage. The needles are configured to have a step, preferably a radiused step, that functions as a stop for the ferrule over which the interior lumen may not pass.
Both ends of the suture are loaded onto individual needles, with the excess suture between the ends contained within the bounds of the device. Functionally, as the aforementioned driver trigger is pulled by the surgeon, the needles are disposed to exit from the window in the stationary lower jaw and to transit a curved path through the grasped tissues until reaching a suture catch disposed upon the upper surface of the moveable upper jaw. The needles, carrying the ferrule and attached suture, pass through the suture catch. Since the ferrule is slidably disposed upon the needle, as the trigger is released, the needle carriage withdraws and the needles attached to the carriage are withdrawn through the tissue, leaving the ferrule and attached suture deposited within the suture catch.
As described previously, the tension on the grasper is released, and the instrument is withdrawn from the operative trocar, trailing the suture behind, and creating a mattress stitch in the grasped tissues.
Now it may be seen by those skilled in the art, the combination of grasping tissues to be sutured and precisely placing a mattress stitch in the grasped tissues while working through a trocar port effects a significant advance in the art. It is therefore an object of the present invention to provide an endoscopic instrument adapted for the grasping of tissues and creating a mattress stitch within those tissues.
It is a further object to provide an instrument that allows for the reloading of additional sutures and suture needles for placement of subsequent stitches.
The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawing.